Time-series regressions including non-linear transformations of an integrated variable are not uncommon in various fields of economics. In particular, within the Environmental Kuznets Curve (EKC) literature, where the effect on the environment of income levels is investigated, it is standard...

How do firms differ, and why do they differ even within narrowly defined industries? Using evidence from six high-tech, manufacturing industries covering a 24-year period, we show that differences in sales, materials, labor costs and capital across firms can largely be summarized by a single,...

How do firms differ, and why do they differ even within narrowly defined industries? Using evidence from a new panel data set for four high-tech, manufacturing industries covering a 10-year period, we show how differences in sales, materials, labor costs and capital across firms can be...

The econometric literature offers various modeling approaches for analyzing micro data in combination with time series of aggregate data. This paper discusses the estimation of a VAR model that allows unobserved heterogeneity across observation unit, as well as unobserved time-specific...